Reconstituted tobacco sheets are known, for example, those produced according to the paper making process disclosed in U.S. Pat. No. 4,182,349. In this process, tobacco stalks, stems, ribs, fines, and other tobacco constituents typically unusable in the manufacture of cigarettes, are reduced to fibers and extracted with hot, aqueous solutions. The hot water-soluble extract is removed, e.g. by screening, and the resultant pulp, containing the tobacco cellulose constituents, is fed to a paper-making apparatus after optional treatments such as homogenization, cleaning, or further screening. Fillers or other additives may be mixed with the pulp prior to feeding it to the paper-making machine. Concentrated hot water-soluble tobacco extract may be added to the raw tobacco sheet prior to its processing into the final tobacco sheet product.
Tobacco sheets produced by the extraction and reconstituted-sheet processes have hitherto been used in small, cut form to extend smoking tobacco in cigarettes and cigarillos, permitting previously unusable fines and ribs to be used as smokable material. Additionally, due to their uniform structure and better mechanical characteristics, reconstituted tobacco sheets have been used as outer wrappers for cigarillos. See, for example, European Patent Application EP-A-495,567, where a reconstituted tobacco sheet made by a paper-making process is used to wrap a smoking product.
However, the use of tobacco sheets as the inner or outer wrapper for smoking products has not been satisfactory for a number of reasons. For example, the starting tobacco material used to make the tobacco sheets, e.g., ribs and stalks having a sufficient cellulose content to form a sheet of sufficient mechanical strength, is inadequate from a sensory standpoint, e.g., aroma and taste, and their dark color is not and attractive or pleasing to the smoker. These smoking products have a cigar or cigarillo taste and not the desired cigarette taste.
Numerous attempts have been made to obviate these disadvantages, including enzymatic preparation of the extract, however, such attempts have hitherto not been successful. Some attempts have led to products which fail to comply with legal requirements for the smoking product.
The use of tobacco sheets as wrappers of smoking products has also been unsatisfactory with respect to tensile strength, water or saliva resistance and with respect to general smoking characteristics, including porosity, burning behavior, ash content and in particular the smoking aroma desired by the smoker.
In the smoking product described in EP-A-495 567, the tobacco sheet is formed from the pulpy extraction of essentially tobacco leaf ribs and fines. To reduce sidestream smoke, only a limited amount of the water-soluble extract is reapplied to the tobacco sheet, namely not exceeding 20% by weight of the tobacco sheet. Therefore, the taste, quality and aroma of this product is not desirable to the smoker.
Products produced using reconstituted tobacco sheets suffer from the disadvantages of unpleasing taste and obtrusive, heavy aroma of side-stream smoke, due to the type of tobacco material used to form the tobacco sheets and are not accepted by many smokers. This deterioration in taste and aroma is worsened in a tobacco product enveloped in two tobacco sheets, because the two sheets account for approximately 20% by weight of the total tobacco product and consequently influence or reduce the taste impression of its main stream smoke considerably, as well as the aroma impression of its sidestream smoke.
The instant invention solves the prior art problem described above with smoking product wrapped with reconstituted tobacco sheets having a satisfactory taste desired and expected by the smoker, and which also improves the quality of sidestream smoke.